(1) Field of the Invention
The invention relates to web stiffening means for channel-shaped framing members having utilization in light-gauge metal framing constructions.
(2) Description of the Prior Art
Light-gauge framing members, such as steel joists, are designed primarily to carry loads applied continuously or uniformly along their lengths. Such framing members are not suitable for carrying loads concentrated at a single point, especially when the bearing area is intensified at less than about twelve inches along the member. As metal thickness to height of member ratio approaches and exceeds a certain value, reinforcement is required at the point of load application to develop full load-carrying capacity without failure or damage to the joist. It has been determined that when the height divided by the thickness reaches 150 and beyond reinforcement is needed. While ratios less than 150 allow webs to provide some load cpacity, stiffening may yet be required to provide necessary load carrying capacity at point loadings.
Previous solutions to inhibit web crippling provide stiffening means for point-type loadings such as at joist supports, partitions supported on a joist and running perpendicular to it, and cantilevered loads and supports. Even though prior art solutions to web strengthening do provide adequate reinforcement, they are hindered in installation by the requirement that they must be placed within channels of the framing members prior to erection. It would therefore be desirable to be able to add reinforcement along framing members, particularly horizontal steel joists, in situ. This is especially helpful in modern highrise constructions wherein wall systems may be relocated or added to suit particular room space needs. Moreover, additional mechanical artifices such as electrical equipment, plumbing, ductwork, conduit, machinery, and other loading changes, may be required to be located or placed in areas not envisioned during initial construction. Along with being able to provide web stiffening means at random locations along joists, it has also become a concern of the industry to quickly install such means without elaborate machination. Accordingly, a simplified configuration for such purposes would be highly preferable. In attaining this goal it would also be desirable to utilize web stiffening means comprising integral compression members suitable for single or double usage to thereby provide point load concentration stiffening for light loads and heavy loads, respectively, by utilization of a similar design throughout for facile installation.
It is therefore a primary goal of the invention to provide web stiffening means for light-gauge metal framing members, especially steel joists, whereby the stiffening means may be inserted within framing member channels, which can remain in place.
It is accordingly an allied goal of the invention to attain web stiffening in already-positioned framing members by the utilization of compression members having simplified configurations for random utilization along framing members throughout a construction at concentrated point load positions.
It is another important goal of the invention to provide web stiffening means comprising compression members, which can be used individually or in doubles, to provide inhibition to web crippling at light point load concentrations or heavy point load concentrations by the same installation techniques.
It is therefore a concomitant goal of the invention to provide such a web stiffening means which can be inserted within a channel of a light-gauge framing member by simply placing the web stiffening means within a channel and rotating it into position along an erected framing construction without requiring disengagement of framing members for insertion within the channel.